Are you trying to get down to bare aluminum?
W/ the condition of the transom, I guess you need to so you can see any potential problems that might have been covered by PO added paint. Plus to repair any thru holes you'd need to go thru the factory original paint too. Is all the paint tough to remove or just the final original layer?
In Calif it will be tough to get your hands on the 'good' strippers [my admiral is 800mi and 6states away, that still made her spidey sense tingle
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Can you use a less aggressive paint remover (typically less expensive)on the PO added layers and use the better stuff ($$$) on just the original paint?
Application temps, air and hull, are important, warm is best, and work in small areas, covered by plastic to improve penetration of the remover and slow its drying out.
If you don't want a bare hull, and there's no evidence of damage that needs repaired, I wouldn't remove any more of the original paint then you think absolutely necessary. All the PO added paint, yeah, outta come off. Sometimes roughing and scuffing the paint will help the initial remover application get thru to soften multiple layers, sometimes.............